The best way to validate the accuracy of a predictive AI system is to use historical testing with past sales data (option D). According to the AAIA™ Study Guide, "historical (or back-testing) is essential for evaluating how well a model would have performed using actual data from previous periods, directly reflecting its predictive validity." This method reveals any gaps or biases in the model by comparing predictions to known outcomes.
Unit testing, load testing, and sensitivity analysis are useful for technical verification and robustness but do not provide direct evidence of prediction accuracy in real-world scenarios.
Reference: ISACA Advanced in AI Audit™ (AAIA™) Study Guide, Section: " AI Model Validation Techniques "